Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
The construction of a modern rotor blade generally includes skin or shell components and one or more internal structural components, such as spar caps and one or more shear webs. The skin/shell, typically manufactured from layers of fiber composite and/or a lightweight core material, forms the exterior aerodynamic airfoil shape of the rotor blade. The spar caps provide increased rotor blade strength by integrating one or more structural elements running along the length of the rotor blade on both interior sides of the rotor blade. Shear webs are structural beam-like components running essentially perpendicular between the top and bottom spar caps and extending across the interior portion of the rotor blade between the outer skins. Spar caps have typically been constructed from glass fiber reinforced composites, though some larger blades may include spar caps constructed from carbon fiber reinforced composites.
The size, shape, and weight of rotor blades are factors that generally contribute to energy efficiencies of wind turbines. For example, an increase in rotor blade size can increase the energy production of a wind turbine. Thus, to ensure that wind power remains a viable energy power source, efforts have been made to increase energy outputs by increasing the length wind turbine blades. For instance, larger wind turbines may have rotor blades 70 meters in radius and larger.
To allow such larger rotor blades to be manufactured and transported, it is often necessary to form the rotor blades in two or more pieces, which must then be assembled at the wind turbine site. For example, known rotor blade assemblies may be formed as a two-piece construction, having both a fully formed tip piece and a fully formed root piece. Thus, to assemble the tip and root pieces, conventional methods require that both the skin/shell components and internal structural components of the pieces be attached simultaneously. Accordingly, the internal structural components of the pieces are often connected blindly, as physical and visual access to such components is blocked by the outer shell components. With such blind connections, it is often difficult and/or impossible to ensure that the internal structural components of the root piece and the tip piece are connected properly. As such, the structural integrity of the rotor blade, particularly at the interfaces of the tip and root pieces, can be affected. Moreover, because of the blind connection of the internal structural components, it is often the case that excess bonding material, such as excessive amounts of adhesive bonding materials, is used to compensate for the lack of access to the internal joints and/or connections of the rotor blade.
Accordingly, there is a need for a rotor blade assembly that provides access to the interior of the rotor blade during assembly thereof.